An external fixator has been known as a device that resets and fixes bones during the treatment of broken bones. In general, an external fixator includes pins that are inserted into bones and members that connect the pins. The members and the pins are fixed not to move relative to each other, so that the bones are reset and fixed.
For example, in Japanese Patent No. 3740640, a plurality of pins are inserted into portions where bones are broken, and the plurality of pins are fixed at each of the portions by clamps. Further, the clamps are connected and fixed to each other by rod-like members that include ball joints at both ends thereof. Japanese Unexamined Patent Application Publication No. 10-43204 also discloses a technique where a plurality of pins are fixed by clamps and ball joints are connected to the clamps.
Furthermore, PCT Japanese Translation Patent Publication No. 2002-534150 and Japanese Unexamined Patent Application Publication No. 2005-65762 also disclose structure where a plurality of pins are fixed by clamps, and further disclose structure where rod-like members connecting the clamps are rotated relative to each other and bent.
Japanese Unexamined Patent Application Publication No. 2004-298253 discloses a technique where pins are fixed by ball joint means used as both balls of ball joints and sockets covering the balls. Japanese Patent No. 3308271 discloses a technique where a clamp is connected to an upper end of a fixing member having a tapered end and a fixing member and a combining member are connected to each other by tightening screws.
In addition, PCT Japanese Translation Patent Publication No. 8-501011, Japanese Patent No. 3308271, Japanese Unexamined Patent Application Publication No. 2005-65762, Japanese Unexamined Patent Application Publication No. 2-215456, Japanese Unexamined Patent Application Publication No. 2002-95675 also disclose various external fixators.